Office 365 is a cloud-based suite of productivity apps like Outlook, Word, PowerPoint, and more.
microsoft365.com/setup is a bundle of services including Office 365, plus several other services including Windows 10 Enterprise. Using Microsoft Word on a smartphone or a tablet might not be your first choice, but it's possible and it's also free. Previously, Microsoft had a standalone Word app for both iOS and Android, but it has now merged Word with Excel and Powerpoint on mobile in the single Microsoft Office application. Microsoft offers Office 365 Education for free through many schools and universities. If you are a student or educator, and your institution is eligible, all you need is a valid school email address. This is a truly free version of Office 365, and you should enjoy this benefit for as long as possible.